Air spring for reciprocating-bed printing presses



.Sept. 15. 1925.

C. B. COTTRELL, 3D

' AIR SPRING FOR RECIPROCATING BED PRINTING PRESSES Filed Oct. 16, 1923 I ATTORNEY-5 Patented Sept. 15, 1925.

UNITED STATES PATENT OFFICE.

CALVERT B. GOTTRELL, an, or FWESTERLYY, RHODE ISLAND, assrenoa To .0. is. cor- TRELL & sons COMPANY, or NEW YORK, N. Y., .A. CORPORATION or DELAWARE.

AIR SPRING FOR RECIPR-OCATING-BED PRINTING PRESSES.

lpplication'filed Gctober 16, 1923. Serial No. 668,860.

To all whom it may concern:

' Be it known that I, CALVERT B. COTTRELL, 3d, a citizen of the United States, and resident of Westerly, in the county of Washington and State of Rhode Island, have invented a new and useful Improvement in Air Springs for Reciprocating-Bed Printing Presses, of which the following is a specifi cation.

The object of my invention is to provide automatic means for controlling the air spring whereby the pressure in the air spring cylinder will be dependent upon the velocity of the bed, eliminating the necessity of the usual mechanical governor; the parts being so operated that after the momentum of the bed has beenchecked, there will be no pressure exerted a ainst the bed driving mechanism and on the return stroke of the bed the formation of a vacuum in the cylinder will be prevented. A further feature of the invention is the expansion of the pressure in the air leak passage and the provision of a mufller so to elimlnate the noise from the exhaust.

A practical embodiment of my invention is represented in the accompanying drawings, in which 1 Fig. 1 represents in longitudinal vertical section so much of a reciprocating bed printing ress as will illustrate my invention.

Fig. 2 represents a detail longitudinal central section on an enlarged scale, through the piston.

Fig.3 represents a section taken in the plane of the line III-III of Fig. 2, looking in the direction of the arrows.

The bed 1 of the press is reciprocated by any well known or approved means, not shown herein. The air spring cylinders, carried b the bed, are denoted by 2, 2, which cyl1nders have open outer ends.

The pair of air spring pistons have their heads 3, 3 arranged in position to enter their respective air spring cylinders. The piston rods 4, 4 are fixedly carried by suitable supports 5, 5. Restricted air. leak passages 6, 6 lead through the piston rods 4, 4 and open through the front of Continuations 7, 7 of these restricted air leak passages lead to acommon muffler 8. It is desirable that the continuations 7, 7, of

i the air leak'passages't), 6 be of greater size than theair leak passages so as to permit the thepiston heads 3,

expansion of air in said continuations, the

further expansion of the air being permitted in the muflier 8. This arrangement entirel eliminates the noise of the exhaust throng these air leak passages" and their continuations as the air spring cylinders engage their respective pistons during the reciprocation of the bed.

Air relief valved passages 9, 9 are provided in the piston heads 3, 3 opening through the fronts thereof. In the present instance I have shown an annular series of holes 9 forming these passages and a single disc valve 1 0 for thepassages in each piston head. These valves 10, 10 are so arranged that the formation of a vacuum in the air spring cylinders will be prevented by the opening of the valves as the air spring cylinders start to withdraw from their engagement with their respective air spring piston heads.

From the above description it will be seen that, as the bed reaches the limit of its movement in either direction and after its momentum has been checked by the air spring, the air leak will practically eliminate the air spring and permit the driving mechanism to freely start the bed on its return movement, the air relief passages serving to prevent any drag by the elimination of the possibility of forming a vacuum in the air chamber.

It is evident that various changes may be resorted to in the form, constructlon and arrangement of the several parts without departing from the s irit and scope of my invention; hence, I 0 not wish to be limited to the paticular embodiment herein shown and described, but- What I claim is:

1. In a reciprocating bed printing press, an air spring cylinder carried by the bed, an

air spring piston, a restricted air leak pasformed head for preventing a vacuum bein oil the an air spring cylinder carried by the bed,-

an air spring piston, a restricted air leak passage opening through the front of the piston head, a mufller for said passage, and an air relief valved passage also opening through the front of the piston head for preventing a vacuum being formed Within the cylinder as it is backed off the piston.

4. In a reciprocating bed printing press,

an air spring cylinder carried by the bed, an air spring piston, a restricted air leak passage of increasing size opening through he front of the piston head, a inufiler for said passage, and an air relief valved passage also opening through the front of the piston head for reventing a vacuum bein a formed Within th off the piston.

5. In a reciprocating bed printing press, a pair of air spring cylinders carried by. the bed, a pair of air spring pistons, restricted air leak passages opening through the fronts of the piston heads, a common uffler for said passages, and air relief va ved pase cylinder as it is backed piston heads for preventing a vacuum sages also opening through the fronts of the being formed Within the cylinders as they are backed off from their respective pistons.

6. In a reciprocating bed printing press, a pair of air spring cylinders carried by the bed, a pair of air spring pistons, restricted air lea passages of increasing size op ing throng passage leading axially through the piston to g the front of the piston head, an annular series of air relief passages leading through the piston head to the front thereof, and a common valve for opening and closing said passages.

In testimony, that I claim the foregoing as my invention, I have signed my name this second day of October, 1913. v

CALVERT B. COTTRELL, 3RD. 

